	* {
	  margin: 0;
	  padding: 0;
	}

	html,
	body {
	  height: 100%;
	  width: 100%;
	  font-family: '幼圆';
	}

	div {
	  width: 800px;
	  height: 40px;
	  margin: 50px auto;
	  background: linear-gradient(#cccccc, #8f8f8f);
	  border-bottom: 10px solid #F56C6C;
	  position: relative;
	}

	div ul li {
	  list-style: none;
	  float: left;
	}

	div ul li a {
	  height: 40px;
	  width: 100px;
	  display: block;
	  text-decoration: none;
	  color: black;
	  font-size: 18px;
	  text-align: center;
	  line-height: 40px;
	}

	div ul li a:hover {
	  background-color: black;
	  color: white;
	}

	.active {
	  background-color: black;
	  color: white;
	}

	div ul li a span {
	  display: none;
	}

	div ul li a em {
	  font-style: normal;
	}

	div ul li a:hover span {
	  display: block;
	}

	div ul li a:hover em {
	  display: none;
	}

	div ul li ol {
	  position: absolute;
	  left: 0;
	  display: none;
	  background: linear-gradient(#cccccc, #8f8f8f);
	  border-top: 10px solid #F56C6C;
	}

	div ul li:hover ol {
	  display: block;
	}